Can Detroit’s urban farms play a role in stemming the floods?

John Meyers, 58, and Nayomi Cawthorne, 26, prune and trellis tomato plants at Feedom Freedom on volunteer day. Credit: Nick Hagen

When Jefferson Chalmers’ Fox Creek canal swelled during the late June downpour, rising waters pushed out many Tiger Dams the city had installed to protect the neighborhood.  

At Feedom Freedom’s gardens on Manistique, water, mud, and sewage rushed through the area’s yards and streets. Beds of collards, beets, kale, blackberry bushes, and more were inundated, rainwater barrels were carried down the street by floodwaters, and the hoop house and pavilion were damaged. 

What remained of the vegetables was so deluged with sewage sludge that founder Myrtle Thompson considered “calling it a wrap” for the season but instead embarked on an intense remediation project. 

“Never have I seen this amount of sewer water in our garden,” she said. “It took a lot out of me. I was walking around in a daze, and it’s still hard to come out here and say, ‘Oh, we got to start over again.’”

Feedom was among the hardest hit local growers, but it’s not alone. Farms and gardens throughout the city reported damage. With climate change-fueled torrential rains regularly straining city infrastructure, flooding has become a fact of life with which many local growers must contend. 

But Detroit’s urban agriculture is also part of the solution, gardeners say. Beds and fields packed with organic matter-rich soil effectively sponge stormwater that would otherwise spill into the city’s strained sewer system. 

A Keep Growing Detroit study found that about 30 of its partner growers’ stormwater collection systems could capture approximately 500,000 gallons of rain annually, while beds stocked with organic matter conservatively absorbed three times as much water as a vacant lot during heavy rain, and sometimes more. 

Growers say urban agriculture should be a significant part of the city’s drainage puzzle, as Detroit Water and Sewer Department and the Great Lakes Water Authority implement systemic infrastructure updates needed to deal with “100-year” storms every few years. 

“Urban gardens and farms that have been tended for a long time manage stormwater better,” said Keep Growing Detroit co-director Ashley Atkinson. “These spaces are so important because when they’re thriving, they can do all these things, including stormwater management, so we need to support them.”

City Commons farm Fields of Plenty illustrated that point after the June storm with side-by-side photos of its flooded 2015 field next to a photo of the same field filled with organic matter-rich top soil absorbing the 2021 downpour. Around the city, Keep Growing Detroit anecdotally found that the more organic matter on partner growers’  fields, the less damage they suffered during the heavy rains than those who had laid down less. 

But there are limitations, and in Jefferson Chalmers, Freedom faces a scenario in which it can’t absorb water spilling out of Fox Creek. The lack of gray infrastructure is putting the farm — and a city asset — in jeopardy. 

“The city needs to immediately take money to build the infrastructure because no one wants to keep going through this over and over again,” Thompson said.

‘A sponge that’s a hundred yards long and two feet thick’

In North Corktown, Brother Nature lost chainsaws, rototillers, a table saw, and other tools stored in its flooded basement. But its fields were a different story. 

As water pooled in the farm’s neighboring lots and spilled into the street, Brother Nature’s fields absorbed the rainfall. Owner Greg Willerer had built up the field several feet above the street by adding compost and mulch over the years, and seven inches of intense rain offered “a big boost” to the farms’ greens, Willerer said. 

“It’s basically a sponge that’s a hundred yards long and two feet thick, and it’s got an amazing capacity for storing water,” he said.

A field doesn’t have to be planted with food crops alone. Long-rooted native plants and flowers are similarly absorbent, and a bit of diversity enhances the stormwater management capabilities while creating pollination tools or helping with urban cooling. The benefits “stack on top of one another,” Atkinson said. 

“If you have one site that has all these interventions happening like deeply rooted plants, deeply rooted perennial vegetables, and really high-quality soil, then it’s going to be a better tool than a vacant lot that was newly turned over a year ago,” she said. “They do all of these beautiful things, but they’re treated as a temporary hobby, and that’s just not the right way to look at things – the framing is wrong.” 

The science backs up the anecdotal evidence. Drummond Carpenter green infrastructure engineer Don Carpenter partnered with KGD to study how effectively growers’ fields absorbed heavy rains. Organic matter can hold more than its weight in water, Carpenter noted, so a pound of compost holds over a pound of water. 

That happens because the matter has higher amounts of effective porosity or pores in which water adheres to the organic material. 

“The more organic matter you have, the more water you hold,” Carpenter said. 

By contrast, a yard with short grass and little organic material will have a short root system that doesn’t break up the clay in the ground, so much less water is absorbed, and the excess runs into the street. The principle also applies to large, rural commodity farms, which typically don’t use much organic matter, Carpenter said.

Implementing urban ag into a citywide stormwater management plan would take buy-in from the city and Detroit Water and Sewerage Department. Keep Growing Detroit has discussed the benefits with the DWSD, and the agency “has been very receptive,” Atkinson said. 

But although the department is spending on green infrastructure, but it’s unclear how much farms, gardens, and similar fields are a part of the plan, and the DWSD didn’t respond to a request for comment from Planet Detroit.

Elsewhere, cities like Boston, Cleveland, New York City, and more are taking concrete steps through zoning changes, tax credits, grants, and various directives to support the implementation of urban agriculture as a stormwater management tool. 

While the city relies on tools like retention ponds, Carpenter noted that fields are more diffuse and productive than a pond. 

“You’re spreading it out and getting several uses out of it instead of just getting a hole in the ground with a single-use,” he said. 

Willerer pointed to a retention pond that the city built and fenced off near Gratiot and Warren Avenues. With a little more planning and vision, it could be supplemented with fields of plants and flowers that absorb water, and that could all be a park that improves the quality of life instead of being a fenced-off eyesore. 

“If you plan this out, then we don’t necessarily need more stormwater ponds — we need more large gardens, more plants, and flowers,” Willerer said. 

Cleaning up Feedom

Several weeks after the storm, cleanup is in full swing at Feedom. Watermelons survived, but Thompson and her crew had to pull up all the kale and beets, and they trimmed the bottom of their berry bushes and tomato plants to get rid of parts that were touched by water. 

They’re also starting over with the farm’s broccoli and kale, corralling all the wood chips that the waters washed away, repairing the hoop house, and generally putting the pieces back together. Brother Nature assisted with a fresh layer of compost that Thompson laid down and said is enough to protect her crops from heavy rain, but not an overflowing creek and nearby river. 

She’s hoping to avert a repeat by building a berm near the creek, but it’s coming out of Feedom’s pocket, and the farm is already facing financial challenges from losing crops. So far, the city hasn’t shown any interest in helping out the farm, Thompson said, or indicated that it’d install a seawall or other more substantial flood protections in Jefferson Chalmers. So far, that’s up to residents.

The June flood marked the third since Thompon moved to the neighborhood around 15 years ago, and the lack of meaningful help from the city is “discouraging,” she said.

“It’s lovely down here by the water, but it’s not safe at this point in terms of economic viability or our health, which is in play every time we have to deal with sewage sludge,” she added. “It makes me sad, and it makes me lose hope in city government and their ability to put neighborhoods and people in front.”